Method of making self-locking nuts



Patented Dec. 21, 1943 UNITED STATES PATENT OFFICE 2,337,372 METHOD OF MAKING SELF-LOCKING NUTS Edward J. Cole, Peekskill, N.

Y., assignor to Cole Machinery Mfg. Corp., a corporation New I York Original application Sep 457,086. Divided and 1943, Serial No.

tember 2, 1942, Serial No.

this application August 7,

Claims. (CI. 86)

25, 1933, and No. 1,966,613, patented July 17, I

1937, although the present nut is considerably simpler in structure and manufacture. In this instance, I am able to operate on conventional standard nut blanks of any desired form and to flare the upper portion of the nut blank bore and consequently spread the crown portion of the nut without cutting or splitting the crown, as disclosed in my prior patents.

The resultant improved standard grip nut produced by this method is standard in all respects, that is, the nut blank is conventional and, aside from the flaring and spreading step, the blank is tapped in a conventional screw tapping machine to form a standard thread therein followed by a compression of the flared and spread parts, so that the upper part of the threaded bore has threads of lesser depth than the remaining threads.

Referring to the accompanying drawing:

Fig. 1 is a top plan of a standard hexagonal grip nut blank, although it will be understood that the invention is equally adaptable for operation on square, wing, or other standard nuts;

Fig. 2 is a vertical section showing the straight bore through the standard nut blank;

Fig. 3 illustrates the standard blank after the upper part of the bore has been flared and the upper portion of the crown spread;

Fig. 4 is a section disclosing the flared and spread standard nut blank after it has been screw threaded or tapped on a conventional screw threading machine;

Fig. 5 illustrates the two depths of the threads which result from reforming or compressing the blank after it has been threaded;

- Fig. 6 is a top plan of the completed sell-locks nut;

Fig. 7 is a side elevation of the completed nut illustrating its standard specifications; and

Fig. 8 shows a. completed square nut produced by the present method.

Specifically, the present method relatesto operating on a standard nut blank I of any desired size, shape, type. form or configuration which is play therebetw'een.

bored, punched, or otherwise cut, to form a straight-sided bore 3 therein, after which the bored nut blank is processed to flare the upper portion 5 of the bore 3 and to spread the upper portion of crown 'l of the nut blank, as shownin Fig. 3. This flaring and spreading may be accomplished in any desired manner, either manually or by passing the blanks through a machine of the character described and claimed in my copending application, Serial No. 447,267, filed June 16, 1942. After the flaring and spreading operation, the blank I is screw threaded throughout the length of the bore, and, due' to the outward flare 5, the screw threaded portion 9 coincident with the length of the flared part 5 is of lesser depth than the lower screw threaded portion II, where the bore is the same diameter as the originally formed bore.

As shown in Fig. 4, the base line of the thread throughout the entire bore is in a vertical plane while the crest line of the thread is in a vertical plane throughout the unflared portion of the bore and follows the flare line in the flared portion of the bore. It will be observed that the crest of the thread in the unflared portion is a.

continuous sharp line or edge and the crest of the thread through the flared portion is progressively wider as the" flare becomes more acute toward the crown of the blank.

Fig. .5 illustrates the threaded blank after the side walls thereof have been recompressed to place the exterior of the nut blank in identical form and size to the original blank disclosed in Fig. l, and here the lesser depth of the screw threaded part 9 is clearly indicated in comparison to the greater depth of the threaded part II in the unflared section of the bore. After compression, the base line of the thread in the unflared portion of the bore remains in a vertical plane while the base line in the flared portion assumes a similar form to that previously maintained by the flare. The crest line 01' the thread of the completed and compressed nut is then in a vertical plane throughout the entire bore.

Thus, when such an improved standard nut blank is applied to a bolt the blunt edge thread portion of the threading binds on the surfaces of the bolt thread and takesup all looseness or This formation also permits the flare and compression to vary when necessary to give an increased spring grip action.

Figures 6 and 7 illustrate the top and sides of the completed grip nut after it has been operated I upon through the several method steps heretofore ass-1,372 v d it will be appreciated that the exdentlcal to a conventional In Fig. 8 a simd standard four-sided or square fter passing through the steps of described an terior configuration is i standard screw threaded nut.

ilarly complete nutis shown a this method.

the bore, and flnally compressing the continuous spread'side portions of the blank and flared end of the bore sufllciently to bring the inner diameter of the threads at said previously flared end of the bore to substantially the same diameter as the inner diameter of the remaining threads. 4. The method of producing a grip nut from and the upper side por ducing an improved nut g the metal of a nut unthreaded bore to uniflare the end of the bore tions of the blank, screw a standard nut blank which comprises boring said blank, uniformly spreading the crown portionof the blank, tapping an uninterrupted screw thread of equal pitch throughout the entire length of said bore in one continuous step, the root of the thread being in a single cylindrical surface and thereafter compressing the continuous spread crown portion of the nut blank to itsfloriginai standard outer configuration whereby-the crest .of the thread is in the same cylindrical surface threading the bore and thereby forming threads of lesser depth at the flared and spread and wherein the root of the thread lies ry element of which in a cylindrical surface, ev

dicularly of the workin a straight line perpen perpendicular to the base of the nut blank and the thread in the crown portion thereof is of less depth. g I

' 5. The method of producing a grip nut from a standard nut blank which comprises the steps nut blank, and flnally compressing portions of the blank ing face of the the continuous spread side and flared end of the bore to bring the crest line of the thread into vertical alinement throughout 2. The method of producing grip nuts as set im' 1 wherein the flnal compressing the nut blank to its original external forth in cla step returnsthod of producing a standard grip nut which consists in spreading the metal of the nut blank at one end of its unthreaded bore to laterally and uniformly flare the end of the bore side portions of the blank, screw ore and thereby forming threads eadand flared end of and the upper threading the b of lesser depth at the spr of forming a uniform diameter bore through said blank from base to crown thereof, increasing the diameter of said boreat one end thereof, screw threading the entire length of the bore with an uninterrupted thread so that the root of the thread thus formed lies in a single cylindrical surface normal to .thebase of the blank and thereafter returning the continuous increased diameter portion of the bore to the diameter of the remaining portion thereof to bring the crest line of the uninterrupted thread into vertical alignment throughout the entire length of the bore and simultaneously return the exterior of the blank to its original standard dimensions.

EDWARD J. COLE. 

